[摘要]:Functionalized heterohelicenes were prepared using sequential olefin metathesis and direct arylation reactions. Functionalization via C-H activation always occurs at the least hindered position of the [5]helicene carbon skeleton. Attempts at blocking the least hindered positions to force arylation at the interior of the helicene skeleton result in decomposition of the starting material. Installation of larger aromatic groups via arylation can form helicenes albeit with limited solubility in common organic solvents. |